Magnetic latch relay



A. E. WOOD, JR., ETAL 3,497,841

Feb. 24,1970

MAGNETIC LATCH RELAY 2 Sheets-Sheet 1 Filed Aug. 30, 1967 Feb. 24, 1970A. E. wooo, JR., ETAL MAGNETIC LATCH RELAY 2 Sheets-Sheet 2 Filed Aug.30, 1967 INVENTORS.

United States Patent Ofitice 3,497,841 Patented Feb. 24, 1970 3,497,841MAGNETIC LATCH RELAY Arthur E. Wood, Jr., San Pedro, Calif. (40 ChuckWagon Road, Rolling Hills, Calif. 90274), and Ralph Edward lgvlarvin,1805 E. Wardlow Road, Long Beach, Calif.

0807 Continuation-impart of application Ser. No. 456,226, May 17, 1965.This application Aug. 30, 1967, Ser. No. 664,419

Int. Cl. H01h 9/02 US. Cl. 335-179 10 Claims ABSTRACT OF THE DISCLOSUREA magnetic latch relay is disclosed in which a pair of electromagnets, acentrally disposed permanent magnet and an associated pivotable armatureare all mounted from a common yoke element which supports the componentsaway from the relay base assembly. The armature is supported by anintermediate plate and is adapted to pivot about a knife edge formedfrom one end of the permanent magnet.

CROSS REFERENCE TO RELATED APPLICATIONS This application is acontinuation-impart of an earlier filed application Ser. No. 456,226,filed May 17, 1965, now abandoned.

This invention relates to improvements in electrical relays particularlyas to mounting and packaging of parts. Exemplary forms of the inventionare disclosed as magnetic latch type relays having a novel and improvedconstruction. The relay is referred to as a latch type relay inas muchas it is a bi-stable device, that is it is stable in two differentpositions which, may, for example, represent the on and off positions ofa switch. In one form of the invention, as described in detail herein,it takes the form of a bi-stable electromagnetic relay providing singlepole, double throw contact operation. In another form of the inventiondouble pole, double throw contact operation is provided. The relay is ofa type wherein the bi-stable operation is achieved through the use of apermanent magnet associated with an electromagnetic means and anarmature. The electromagnetic means can, of course, be energized andde-energized. In the invention as described herein, the energization andde-energization of the electromagnetic means changes the magnetic fluxin a manner so as to cause the armature to shift between its bi-stablepositions. The flux produced by the permanent magnet is utilized to holdthe armature in its two stable positions. The magnetic fields areutilized in this way so that the result is realized without the use ofbiasing springs or any other similar types of devices. Only a singleermanent magnet is used. In the forms of the invention as describedherein, two electromagnetic cores and associated windings are used. Thepermanent magnet and the electromagnetic cores and windings are arrangedin a symmetrical relationship. The armature is preferably symmetricallyarranged about a pivot point at one end of the permanent magnet. In thepreferred form of the invention the magnetic cores are mounted upon acommon magnetic yoke which yoke also supports the permanent magnet. Thisassembly is supported by a base member or contact header.

A special feature of both forms of the invention is the particularmanner and construction utilized in the packaging of the parts of theassembly. A significant aspect of this construction is that there isprovided a magnetic yoke upon which are supported the magnetic cores,the coils and the permanent magnet and the armature. These parts as wellas the contacts and terminals are contained within the cap or coverwhich is attachable to a circular base or header. The yoke has legs thatare secured to the header so that the yoke with its attached partsstands off from the header. The terminal members extend through theheader, thence through insulating members into the space between theheader and the part is carried 'by the yoke. This provides an extremelysimple, compact way of packaging and holding the parts in their properrelationship. This structural relationship is a primary feature of theherein invention and may be utilized in relays other than latch typerelays.

In light of the foregoing, a primary object of the invention is toprovide a relay characterized in having an improved arrangement ofparts, mounting thereof, and containment in a circular housing having aheader wherein the essential parts are carried by a magnetic yoke havinglegs whereby it stands off from the header.

A further object of the invention is to provide an improved bi-stablelatch type relay, utilizing a single permanent magnet which is carriedby the magnetic yoke member, and the relay having contacts, providingfor either single pole, single throw operation or double throwoperation. In either relay operation, however, contacting means ispositioned between the header and the part is carried by the magneticyoke.

In the forms of the invention described in detail herein, the armatureis preferably mounted upon a knife ed e at the end of the permanentmagnet which is positioned between the relay windings. In one form ofthe invention the armature is held on the knife edge by way of metalfingers, brackets or clips extending from a plate positioned at the endsof the windings or coils through which the cores extend. These fingersor clips engage with cutouts on opposite sides or edges of the armatureallowing it to move angularly on the knife edge. In this form of theinvention, the knife edge is received in a V-notch in the armature. In afurther and preferred form of the invention, instead of having theV-notch in the armature, a transverse groove is provided in the armatureon the side opposite from the knife edge support. A transverse pivotshaft, having its ends journalled in brackets extending from the platewhich is carried by a tachment to the coils fits in the transversegroove cores. This armature mounting thus described has improvedreliability and effectiveness.

Further objects and additional advantages of the invention will becomeapparent from the following detailed description and annexed drawingswherein:

FIGURE 1 is an elevational View of the exterior of one form of theinvention;

FIGURE 2 is a cross-sectional view taken through the form of theinvention shown in FIGURE 1;

FIGURE 3 is a sectional view taken along the line 33 of FIGURE 2;

FIGURE 4 is a sectional View taken along the line 4-4 of FIGURE 2;

FIGURE 5 is an exploded view of the form of the invention shown inFIGURES 1, 2, 3 and 4;

FIGURE 6 is a sectional view of a modified form of the invention; and

FIGURE 7 is a partial exploded View of the form of the invention shownin FIGURE 6.

The relay of this invention is highly adapted to miniaturization and hasmany applications in different types of components and environments. Anexemplary form of the relay as shown in FIGURE 1 comprises a base orheader 10 and a cap or cover 12 having a flange 14 adjacent the base 10.The cap or cover 12 encloses the mechanism of the relay. Extendingoutwardly from the base 10 are a group of connecting leads designatedcollectively at 16.

As shown in the cross-sectional view of FIGURE 2 and in FIGURE 5, thebase 10 has a portion 18 of smaller diameter so as to provide anextending flange 19. The cap 12 fits over the part 18 of smallerdiameter with the flange 14 flush against the flange 19. Numeral 21designates an extending tab which indicates the position of the armatureand the contacting mechanism within the housing 12.

Supported within the housing are electromagnetic cores, electromagneticwindings and a permanent magnet. Numeral 24 designates a common magneticyoke or yoke frame which supports the magnetic cores. The frame 24 hasextending legs 27 and 28 (FIGURE which are received in cutouts 31 and 32in the header or base member and which may be welded thereto. Themagnetic yoke 24 supports cylindrical cores 33 and 34 which are suitablyattached to the top of the yoke 24 as shown at 35 and 36 (FIGURE 2). Thecore 33 has an end flange 40. Numeral 42 designates an electromagneticwinding which is wound on the core 33, the winding being encased in asuitable insulative sheath 43.

The core 34 has an end flange 50. Numeral 52 designates anelectromagnetic winding on this core, this Winding having a suitableinsulative sheath 54. The cores 33 and 34 have end parts 55 and 56 whichfit through apertures 57 and 58 in the base or bottom of yoke or frame24. See FIGURE 5.

The armature is designated at 60. In this form of the invention, it hasa shape or configuration as shown in FIGURES 3 and 5 having side cutoutsas designated at 61 and 62 (FIGURE 3). A support plate 46 has openings47 and 48 through which the cores 33 and 34 extend (FIGURE 5) plate 46has a center slot or opening 63 from which depend legs 66 and 68 havingend tabs 70 and 71 which are bent over to engage the armature 60 asshown in FIGURE 3. Legs 66 and 68 fit in cutouts 61 and 62. Between theelectromagnetic cores and windings there is an elongated permanentmagnet 74 supported from the yoke frame 24. It has a knife edge 75formed at its end. The armature 60 is shaped as may be seen in FIGURE 2so that when one portion as shown, contacts an end face of the core 33the other portion of the armature is spaced from the end face of thecore 34 to pro vide an air gap therebetween. The armature 60 has anintermediate transverse groove 77 which engages the knife edge 75 sothat the armature has a pivotal mounting at the end of the permanentmagnet 74. From the foregoing it may be seen that the legs 27 and 28 ofmagnetic yoke 24 stand it ofi from header 10. The yoke 24 carries andsupports the coils, and armature. The contacts are located in the spacebetween the winding assembly and the header with the terminals extendingthrough the header into this space.

The armature 60 has a stem 78 attached to it having a ball 79 at its endpositioned to engage and operate a contact as will be described. Numeral81 designates a second stem with a ball 82 attached to it for similarpurpose. As may be observed the armature has a pivotal mounting providedby the knife edge 75, groove 77 and the tabs 70 and 71.

The armature in its pivotal movements operates a flexible contact strip85 which is secured to the end 86 of a conductive contact pin or stemwhich extends through an insulator 88 in the base or header 10. Theflexible contact strip 85 selectively engages one of two curved contactmembers 91 and 92 which are attached respectively to contact pins orstems 94 and 95 as shown in FIG- URE 4. Stems 94 and 95 extend throughinsulators 97 and 98 respectively in the base or header 10.

Additional current pin leads are provided as designated at 100 and 101extending through insulators 103 and 104. Numerals 108 and 109 designateadditional current pin leads extending through the insulators 111 and112 respectively in the base or header 10. These leads are for thepurpose of conducting current to the electromagnetic windings 42 and 52.The windings are wired so that they may be individually energized toproduce magnetic flux in a direction to neutralize the permanentmagnetic flux in either of the cores 33 or 34, as will be described.

FIGURE 2 shows the armature 60 in one of its positions in which it is incontact with the end face of the core 33. The other end of the armature60 forms an air gap with the end face of the core 34. In this positionthe insulated actuator ball 82 on the armature 60 presses one end of theflexible contactor into engagement with the contact member 92. As willbe observed by those skilled in the art, the relay provides for singlepoles, double throw contacting operation. Double pole, double throwcontacting operation can of course be provided for as shown in theembodiment of FIGURES 6 and 7. It will be observed that the relay asdescribed in detail herein accomplishes all of the objects andadvantages as described herein as well as having many additionaladvantages that are apparent from the detailed description. f

In the position shown in FIGURE 2, the armature 60 being in contact withthe end face of the core 33 provides a low permeability flux path forthe flux from the permanent magnet 74 through the armature, the core 33and the yoke 24. This flux holds the armature in the position shown sothat it is stable in this position. To reverse the position of therelay, the electromagnetic winding 42 may be energized in a direction(or polarity) so as to neutralize the flux in the core 33. The armature60 is not then held against the core 33. The flux of the permanentmagnet 74 in the air gap between the other end of the armature and thecore 34 is suflicient to cause the armature to rotate about its pivotpoint so that its other end is brought into contact with the end face ofthe core 34. Armature 60 is then held in that position. In this positionthe contact member 85 is brought into engagement with the contact 91. Toagain change the position of the armature, the winding 52 may beenergized in a direction, that is with a polarity to cancel orneutralize the flux in the core 34.

FIGURES 6 and 7 show a modified form of the relay. This form of theinvention provides for double pole, double throw contacting operation.The mounting of the armature is different as will be describedhereinafter. Those parts of the relay of FIGURES 6 and 7 which are alikeand correspond to similar parts in the previous embodiment areidentified by the same reference characters. In this form of theinvention the magnetic yoke 24 is like that of the previous embodimenthaving legs 27 and 28 which fit into the cutouts 31 and 32 in the header10.

In this form of the invention, the armature is designated at 100. It islike the armature 60 of the previous embodiment except as follows. Onthe side of the armature opposite from the knife edge 75 it has atransverse groove 101 adapted to receive a pivot shaft 104. The otherside of the armature is positioned directly against the knife edge 75without a V-notch in the armature. The plate 106 is slightly differentthan the corresponding plate 46 of the previous embodiment. It hasopenings 107 and 108 through which the cores 33 and 34 extend as in theprevious embodiment. It has an intermediate slot or cutout 111 fromwhich extend brackets 114 and 115 having apertures therein, in which theends of the shaft 104 are journalled with the shaft positioned in thegroove 101 as shown in FIGURE 6. Thus as can be seen, the armaturerotates angularly about the knife edge 77, the shaft 104 having slightclearance in the openings in the brackets 114 and 115 to allow thismovement. The armature and shaft 104 are normally urged against theknife-edge 75 by the magnetic attraction so that the shaft is normallyin a tangential relationship at the bottom of the aperture in thebrackets 114 and 115.

In FIGURE 7, numerals and 121 designate a pair of flexible contactstrips which are engageable to be operated by the balls 79 and 82carried by the armature 100. Strip 120 is carried at the end part of aterminal 124 which extends through an insulated member 125 in the header10. This end operates between two curved contact members 127 and 129.Contact 127 is carried by a terminal 130 which extends through aninsulator member 131 in the header 10. Contact 129 is attached to andcarried by terminal 133 extending through an insulating member 134 inthe header 10.

Contact strip 121 is carried by terminal member 140 extending throughinsulating member 141 in header 10. The end of strip 121 operatesbetween curved contact members 145 and 146. Contact member 145 iscarried by terminal member 148 extending through an insulating member inheader 10, and contact 146 is carried by terminal member 147 extendingthrough an insulating member in the header 10. Additional terminalmembers as necessary are provided, carried by and extending through theheader 10.

The operation of the relay of FIGURES 6 and 7 is similar to that of theprevious embodiment and therefore the description of operation need notbe repeated in detail. However, as explained, the contact operation isdouble pole, double throw. The armature is held in position and operatesas described without the requirement of having a V-notch in thearmature.

From the foregoing those skilled in the art will observe that the relayof both embodiments is stable in its two positions and in each positionit is held stable by the flux from the permanent magnet in a flux pathincluding either one of the cores 33 or 34. By the reason of thesymmetrical relationship, the same permanent magnet is utilized toprovide flux for causing the armature to change its position and forholding it stable in either one of its two positions.

From the foregoing those skilled in the art will observe andunderstandthe construction, and mounting of the parts, and willappreciate that the packaging thereof is alike in the two embodiments ofthe invention. The magnetic yoke itself serves as the supporting framefor the parts of the relay, its legs standing these parts off from theheader. The contacts are conveniently spaced just inside the headerbetween it and the winding assembly. This provides for a verysimplified, compact and effective arrangement of parts.

From the foregoing those skilled in the art will readily understand thenature of the invention and its construction, and the manner in whichits objects and advantages as outlined in the foregoing are realized aswell as the many additional advantages that are apparent from thedetailed description.

The foregoing disclosure is representative of preferred forms of theinvention and is to be interpreted in an illustrative rather than alimiting sense, the invention to be accorded the full scope of theclaims appended hereto.

What is claimed is:

1. A miniaturized magnetic latch relay comprising:

a support header having at least one pair of fixed contacts positionedabove the header and coupled to contact pins extending through theheader, a movable contact mounted on an additional contact pin extendingthrough the header, said movable contact being adapted to pivot intoelectrical contact with one or the other of said fixed contacts inresponse to pivotable movement of an armature positioned for insulatedengagement with the movable contact;

a magnetic yoke having a plate member parallel to the header andprovided with substantially opposed downwardly depending elongated legsadapted for attach ment to the header;

an armature;

an electromagnetic means for pivotably moving said armature intoengagement with said movable contact and latching the armature at saidpivoted position, the improvement comprising:

said electromagnetic means is mounted from said yoke plate free fromcontact with said base and out of contact with said legs wherebydistortion of said legs does not disrupt the cooperative relationshipbetween said electromagnetic means, said armature and said contacts,said electromagnetic means comprising:

a permanent magnet fastened to said yoke plate and aligned free ofcontact between said opposed legs;

a pair of electromagnetic coils positioned on opposite sides of saidpermanent magnet;

means pivotably mounting the armature to the permanent magnet andcompleting a partial magnetic circuit with the permanent magnet throughthe armature; and

a magnetic core means for each coil, said core means mounting thearmature mounting means, and the electromagnetic coils to said yokeplate also free of contact with said yoke legs, said cores serving tocomplete a magnetic circuit for said armature in latched positionsthereof.

2. The combination of claim 1 wherein said permanent magnet has a knifeedge formed at one end, said combination further comprising:

means included in said mounting means for supporting the armature inpivotal engagement with said knife edge.

3. The combination of claim 2 wherein said armature supporting meanscomprises:

an armature support plate member having extending bracket clips engagingsaid armature and holding it in position to pivot with respect to saidknife edge, said support plate member being supported by said cores.

4. The combination of claim 1 wherein said armature has a transversegroove in a side opposite from said knife edge and said supporting meanscomprises:

a shaft engageable in said groove;

means for supporting said shaft with the armature in a position to pivotabout said knife edge.

5. The combination of claim 4 wherein said shaft supporting meanscomprises:

an armature support plate member supported by said cores, said armaturesupport plate member having a bracket pair extending therefrom, eachbracket having an aperture therein through which an end of said shaft isjournalled.

6. A miniaturized magnetic relay comprising in combination:

a base member;

electromagnetic means including two electromagnetic coils, each coilbeing provided with an associated core;

a permanent magnet positioned between said two coils;

a magnetic yoke including a magnetic plate member positionedsubstantially parallel to said base member and having at least twoelongated legs supporting said plate member away from said base member,the electromagnetic coils, associated cores and the permanent magnetbeing supported from said magnetic plate member off from said basemember, the coils, associated cores and the permanent magnet being outof contact with said legs;

armature support means supported by said cores; and

an armature pivotally mounted on said support mea s and adapted toselectively contact either one or the other of said cores depending uponits pivoted position.

7. The combination of claim 6 wherein said permanent magnet has a knifeedge formed at one end; said combination further comprising:

said support means mounts the armature for pivotal engagement with saidknife edge.

8. The combination of claim 6 wherein said armature support meansfurther comprises:

an armature support plate member having extending bracket clips engagingsaid armature and holding it 7 in position to pivot with respect to saidknife edge, said support plate member being supported by said cores.

9. The combination of claim 16 wherein said armature has a transversegroove in a side opposite from said knife edge and said support meanscomprises:

a shaft engageable in said groove;

means for supporting said shaft with the armature in a position to pivotabout said knife edge.

10. The combination of claim 9 wherein said shaft supporting meanscomprises:

an armature support plate member supported by said cores, said armaturesupport plate member having a bracket pair extending therefrom, eachbracket having an aperture therein through which an end of said shaft isjournalled.

References Cited UNITED STATES PATENTS 3,121,148 2/1964 Wellsctal.335--80XR 2,955,174 10/1960 Richert 335-80 5 2,941,130 /1960 Fischeretal 33s 23o 2,082,493 6/1937 Hartman 335-181 FOREIGN PATENTS 0 155,23310/1963 Russia. 1

U.S. Cl. X.R.

UNITED STATES PATENT OFFICE CERTIFICATE ()F CORRECTION 3,497 ,841February 24, 1970 Patent No. Dated I v d Arthur E. Wood, Jr. et a1 It iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

Column 2, lines 6 and 7, and line 24, "part is carried",

each occurrence, should mead parts carried line 43 after "to the coils"insert and Column 4, line 11, "poles" should read pole line 70,"aperture" should read apertures Column 7, line 4, "claim 16" shouldread claim 6 Signed and sealed this 1st day of December 1970.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. WILLIAM E. SCHUYLER, JR. Attesting OfficerCommissioner of Patents

